WiringPi Serial And Shiftout

Gordon strikes again, releasing a new WiringPi which not only includes the ShiftOut functions I was attempting to add, but also a whole delightful library of Serial goodness.

I've rolled both of these things into a new version of the WiringPi gem, which has also undergone some significant architectural changes favouring a more Object Orientated design. I've incremented the major version to reflect this.

To use GPIO functions you should create an instance of the WiringPi::GPIO class: